Basically if the command is available, it is fair game to use it.
Except there are apparently some exceptions.
In one of the exceptions, there is a nice big block of warning text that alerts you that you should xhelp before using a certain type of object in certain parts of the city.
Another exception is vehicle theft. Although it is fully possible without admin intervention, it is not "allowed". But unlike the using certain objects example above, there is not any warning text appended to the command(s) or vehicle object verb(s) to let new players know that they should xhelp ahead of time.
What else are we supposed to get permission for before we do it?